Antimicrobial Dihydroflavonols and Isoflavans Isolated from the Root Bark of Dalbergia gloveri.

Three new dihydroflavonols, gloverinols A-C (1-3), a new flavon-3-ol, gloverinol D (4), two new isoflavans, gloveriflavan A (5) and B (6), and seven known compounds were isolated from the root bark of Dalbergia gloveri. The structures of the isolates were elucidated by using NMR, ECD, and HRESIMS data analyses. Among the isolated compounds, gloverinol B (2), gloveriflavan B (6), and 1-(2,4-dihydroxyphenyl)-3-hydroxy-3-(4-hydroxyphenyl)-1-propanone (10) were the most active against Staphylococcus aureus, with MIC values of 9.2, 18.4, and 14.2 µM, respectively.

Prenylated Isoflavanones with Antimicrobial Potential from the Root Bark of Dalbergia melanoxylon.

Dalbergia melanoxylon Guill. & Perr (Fabaceae) is widely utilized in the traditional medicine of East Africa, showing effects against a variety of ailments including microbial infections. Phytochemical investigation of the root bark led to the isolation of six previously undescribed prenylated isoflavanones together with eight known secondary metabolites comprising isoflavanoids, neoflavones and an alkyl hydroxylcinnamate. Structures were elucidated based on HR-ESI-MS, 1- and 2-D NMR and ECD spectra. The crude extract and the isolated compounds of D. melanoxylon were tested for their antibacterial, antifungal, anthelmintic and cytotoxic properties, applying established model organisms non-pathogenic to humans. The crude extract exhibited significant antibacterial activity against Gram-positive Bacillus subtilis (97% inhibition at 50 µg/mL) and antifungal activity against the phytopathogens Phytophthora infestans, Botrytis cinerea and Septoria tritici (96, 89 and 73% at 125 µg/mL, respectively). Among the pure compounds tested, kenusanone H and (3R)-tomentosanol B exhibited, in a panel of partially human pathogenic bacteria and fungi, promising antibacterial activity against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and Mycobacterium showing MIC values between 0.8 and 6.2 µg/mL. The observed biological effects support the traditional use of D. melanoxylon and warrant detailed investigations of its prenylated isoflavanones as antibacterial lead compounds.

Expanding the reach: ethnobotanical knowledge and technological intensification in beekeeping among the Ogiek of the Mau Forest, Kenya.

BACKGROUND: Initiatives for beekeeping intensification across the tropics can foster production and income, but the changes triggered by the introduction of modern beehives might permeate traditional knowledge and practices in multiple ways, and as such should be investigated and understood. We conducted an ethnobotanical study in the Eastern part of the Mau Forest among Ogiek beekeepers who customarily practice forest beekeeping and who are involved in a project aimed at the modernization of their beekeeping activities. We aimed to document the beekeeping-associated ethnobotanical knowledge, exploring the relationships and complementarity between modern and traditional knowledge and practices. METHODS: Field research was carried out through semi-structured interviews with 30 Ogiek beekeepers and 10 additional stakeholders. We collected ethnobotanical data about plants used for beekeeping purposes, and ethnographic information on traditional and modern beekeeping systems. RESULTS: We report 66 plant species, distributed across 36 botanical families representing 58 genera, important as melliferous, for the construction and placing of hives, attracting bees, and harvesting and storing honey. Dombeya torrida (J.F.Gmel.) Bamps, Juniperus procera Hochst. ex Endl., and Podocarpus latifolius (Thunb.) R.Br. ex Mirb. are the species with the most mentions and the highest number of uses. Our study reveals that the Ogiek possess a detailed knowledge of the forest's flora, its importance and uses and that this knowledge underpins beekeeping practices. Under the influence of external actors, the Ogiek have progressively adopted modern versus traditional log hives and moved beekeeping out of the forest into open areas of pastures and crop fields. Beekeepers are also experimenting with combinations of practices borrowed from modern and traditional beekeeping systems, particularly in the field of hive construction and in the criteria to set up apiaries. CONCLUSIONS: The study indicates a complementarity and an incipient hybridization of traditional and modern beekeeping, in a way that suggests that modern beehives are instrumental in expanding the reach of beekeeping into deforested and cultivated areas. The study also points to the existence of a rift in the effects of beekeeping intensification on the livelihoods of the Ogiek and on their relationship with the forest. We argue that this intensification might be improving the former but weakening the latter, carrying the associated risk of erosion of traditional forest-based ethnobotanical knowledge.